Power Matrix - Crown DC-300A II Reference Manual

DC-300A II Power Amplifier
Construction
Dimensions: 19 inch (48.3 cm) standard rack mount
width (EIA std. RS-310-B); 7 inch (17.8 cm) height; 10.5
inch (26.7 cm) depth behind front mounting surface;
0.625 inch depth in front of mounting surface.
Weight: Net weight is 40 pounds, 11 ounces (18.5 kg);
Shipping weight is 45 pounds, 0 ounces (20.3 kg).
Finish: Carbide black front panel, splatter-coat black
In an effort to provide you with as much information as possible about the high power-producing capabilities of your amplifier, we have created
the following Power Matrix. All specifications found in these tables are valid for 120 VAC, 60 Hz models and are guaranteed for three years. Some
spaces in the tables are left blank because we do not provide this same guarantee for those conditions—however, your amplifier will perform well
under all conditions listed in the table.
Power Specifications
When measuring power, 0.1% THD appears to be the industry standard for distortion. One of the maximum average power columns shown in the
power matrix is measured when THD rises to 0.1% so you can easily compare Crown specifications to those of other manufacturers. But this high
level of distortion actually allows for some clipping which is undesirable. Full-bandwidth maximum average power measured at 0.05% THD
provides more reasonable, non-clipped conditions. Crown provides this specification with the hope that other manufacturers will also start
providing specifications that correspond to the way amplifiers are used in the real world—without a clipped input signal.
Many manufacturers publish power specifications with a tolerance of ±1 dB or worse. That means their amplifier can deviate more than 20% in
output! A 100 watt amplifier would meet their specification if it only produced 79.4 watts. Other manufacturers qualify their specs by saying they
are "typical, " "subject to manufacturing tolerances, " "single channel driven" or that they are specified with "fuses bypassed. " Each of these
statements effectively removes any performance guarantee. We take a different approach at Crown—our published specifications are guaran-
teed for three years. Further, because our "in-house" specs are more stringent than our published specs, every Crown amplifier will exceed its
published specs. We believe you should get what you pay for.
FTC Continuous Average
Power at 0.1% THD
Dual-Mono
(See note 1)
Mode
20Hz-20kHz
4 250
Dual
8 165
(both channels
driven)
16 95
8 545
Bridge-Mono
(balanced output)
16 340
Notes:
1. Continuous power in the context of Federal Trade Commission testing is understood to be a minimum of five minutes of operation. Harmonic
distortion is measured at the RMS sum total as a percentage of the fundamental output voltage. This applies for all wattages greater than 0.25
watts.
2. A 1 kHz sine wave is presented to the amplifier and the output monitored for nonlinear distortion. The level is increased until the THD reaches
0.1%. At this level the average power per channel is reported.
3. A sine wave is presented to the amplifier over the range from 1 Hz to 20 kHz and the output is monitored for nonlinear distortion. The level at
each frequency is increased until the THD reaches 0.05%. At this level the average power per channel is reported.
4. A single cycle of sine wave is presented to the amplifier and monitored for nonlinear distortion. The average power during the burst is reported.
Speakers must be able to withstand this level if they are to be safely used with this amplifier.
5. A 40 millisecond burst or two cycles of sine wave (whichever is of greater duration) is used and the power computed as the average power
during the burst. The duty cycle of this test is 10 percent. This power level is a measure of how loud an amplifier is as perceived by the hearing
process.
6. EIA standard RS-490 (both channels driven).
Crown specifications are guaranteed for three years.
D C - 3 0 0 A I I
Max Average Max Average
Power at Power at
0.1% THD 0.05% THD
(See note 2) (See note 3)
1 kHz 1 kHz 1 Hz-20 kHz
295 305
175 175 155
100 100
595 610
355 355 310
Fig. 6.1 Power Matrix
chassis and top cover.
Chassis: All aluminum construction for maximum heat
conduction and minimum weight. Heavy aluminum
front panel is a single extrusion.
Heat Sinking: Massive black-anodized heat sinks are
thermally joined with the chassis, thereby utilizing the
entire amplifier as a heat sink.
Single Cycle Tone Burst
Watts at <0.05% THD
(See note 4)
20 Hz 50 Hz 1 kHz
260 350 405
185 195 215
590 660 785
355 370 415
40 mS Tone Burst
Watts at <0.05% THD
at 1% THD
(See note 5)
(See note 6)
20 Hz 50 Hz 1 kHz
260 310 300
180 185 180
595 615 585
350 355 345
Page 19
EIA Watts
310
185
100
625
370